An unanswered question about Lexical Distance is how is it defined?
I don’t really know how to read these charts for comparison, since the two language pairs that I know that are similar, aren’t listed here, namely German and Yiddish, and Hebrew and Aramaic. Both pairs are lexically close, but I just don’t know how close.
My source for the lexical distances Lexical Distance Among Languages shown here are from Prof. Tyshchenko’s research. Sadly, I have not read any literature of his that clearly defines 1 Lexical Distance. Maybe Sergei Starostin’s definition Glottochronology was used or the Levenshtein distance? But that would not give you distances between 15 and 90 but constants between 0 and 1 or percentages. Have resulting constants been multiplied with a factor, is this a percentage of divergence or is there another definition? I have tried to reach out to the Language Museum at the University of Kiev for an answer and will share it here if I get an answer.
One logical definition could be one vowel shift, consonant shift or a rule change is the equivalent to 1 Lexical Distance. So if you were take a text in one language implement one shift, rule change and loanwords wave after the other, then it would take 49 steps to change an English text into a (comprehensive) German text or 25 steps to change a Dutch text into a German text. These steps are similar to a joke that has been circulating the web for the last two decades about the implementation of English as the sole language in the European Union. The joke text progressively implements vowel and consonant shifts until the gibberish sounds like German.
The United/European Union Commissioners have announced that an agreement has been reached to adopt English, rather than German, as the preferred language for American and European communications.
As part of the negotiations, Her Majesty’s and the United State’s Government conceded that English spelling had some room for improvement and they developed a five-year phased plan for what will be known as Euro-English.
In the first year, “s” will be used instead of the soft “c”. Sertainly, sivil servants will resieve this news with joy. Also, the hard “c” will be replaced with “k”. This will make English konform more klosely to German, which is a more proper language. Not only will this klear up konfusion, but typewriters kan have one less letter.
There will be growing publik enthusiasm in the sekond year, when the troublesome “ph” will be replaced by “f”. This will make words like “fotograf” 20 persent shorter.
In the third year, publik akseptanse of the new spelling kan be expekted to reach the stage where more komplikated changes are possible.
Governments will enkorage the removal of double letters, which have always ben a deterent to akurate speling. Also, al wil agre that the horible mes of silent “e”s in the languag is disgrasful, so those would be dropd.
By the fourth year, peopl wil be reseptiv to steps such as replasing “th” with “z” and “w” with ” v”. Vuns agan, zis is mor in kunformuns wiz German.
During ze fifz year, ze unesesary “o” kan be dropd from vords kontaining “ou”, and similar changes vud of kors be aplid to ozer kombinations of leters.
After ze fifz yer, ve vil hav a reli sensibl riten styl. Zer vil be no mor trubls or difikultis and evrivun vil find it ezi tu understand ech ozer. Ze drem vil finali kum tru.
This version is from The Farther Side. There are other versions also in other languages, for example one between German and Dutch which is a lot easier to pull off than between English and German (again 25 steps versus 49).
So if I were to determine the lexical distance between Standard German and Yiddish with a quote by Max Weinreich then it would take me only 5 Lexical Distances to complete it.
Standard German: “Eine Sprache ist ein Dialekt mit einer Armee und Flotte.”
1: “a Sprache ist ein Dialekt mit an Armee und Flotte.”
2: “a schprache ist a dialekt mit an armee und flotte.”
3: “a schprache ist a dialekt mit an armej und flotte.”
4: “a schprache ist a dialekt mit an armej und flot.”
5: “a schprach is a dialekt mit an armej un flot.”
Yiddish: “a schprach is a dialekt mit an armej un flot.”
אַ שפּראַך איז אַ דיאַלעקט מיט אַן אַרמיי און פֿלאָט
Whereas Sprache to schprache could be skipped because the pronunciation of Sprache is [ˈʃpraːxə]
Edit September 4th 2015:
Apparently the earliest version of the joke was penned by Mark Twain or by M.J. Shields.
A Plan for the Improvement of English Spelling
For example, in Year 1 that useless letter “c” would be dropped to be replased either by “k” or “s”, and likewise “x” would no longer be part of the alphabet. The only kase in which “c” would be retained would be the “ch” formation, which will be dealt with later. Year 2 might reform “w” spelling, so that “which” and “one” would take the same konsonant, wile Year 3 might well abolish “y” replasing it with “i” and Iear 4 might fiks the “g/j” anomali wonse and for all. Jenerally, then, the improvement would kontinue iear bai iear with Iear 5 doing awai with useless double konsonants, and Iears 6-12 or so modifaiing vowlz and the rimeining voist and unvoist konsonants. Bai Iear 15 or sou, it wud fainali bi posibl tu meik ius ov thi ridandant letez “c”, “y” and “x” — bai now jast a memori in the maindz ov ould doderez — tu riplais “ch”, “sh”, and “th” rispektivli. Fainali, xen, aafte sam 20 iers ov orxogrefkl riform, wi wud hev a lojikl, kohirnt speling in ius xrewawt xe Ingliy-spiking werld.